Advice sought: '71T not starting

[PrairieDriver]

It is getting cold here in Chicago and with snow forecast I've been trying to get in a last few drives before putting my car into storage. Unfortunately, I haven't been able to start the car in either of my last two attempts (yesterday and today, each of which have had garage temperature of around 45 degrees). Each time the ignition fires up and brings the car to a rough idle. After sputtering for a few seconds, the engine dies. I am able to re-fire the ignition about three times (resulting in the engine starting again and then stalling). Unfortunately, after about the fourth attempt, nothing happens -- the ignition doesn't seem to fire and the engine doesn't turn over (but the light does illuminate on the oil temperature gauge).

Note that my car is a '71T with Zenith carbs. Even in the summer a cold start requires a few cranks. I keep the battery on a tender but I still suspect that my battery may be short of "juice" and that I need a tune up.

I'd appreciate any coaching to get the car started so I can get it into storage before snow comes!

HH

[Haasman]

PrairieDriver (like the handle)

there comes to mind a lot of basic questions such as-

-how was it running when you last drove it.
-how long ago was that?
-does the car sit for long periods of time?
-when was it fueled last?

I'd take the battery tender off and use a volt ohm meter and test the battery charge, before trying to start and after attempts.

[PrairieDriver]

Haasman: thanks for your response. Quick answers to your questions:

- how was it running when last driven? Fine. I drove it for about 25 minutes
- how long ago was that? Tuesday (5 days ago)
- does the car sit for long periods? It sat for two weeks prior to that. Think of it as a weekend driver with occasional missed weeks if I am out of town
- when was it fueled last? About 1 month ago. It has about 1/2 tank

I have a voltmeter that I sort of now how to use. With a Youtube refresher, I should be able to get a reading! HH

[PrairieDriver]

The voltmeter reads 13.01 on both batteries (assuming I followed the directions correctly -- it seemed straightforward, so hopefully I didn't screw up the measurement).

Thanks for any further guidance. HH

[edmayo]

you said "the engine doesn't turn over" I assume you mean that the starter is NOT cranking the engine over. So we have a possible bad starter, bad ignition switch, dead battery , or some fault in the circuit in between them. Since you have 13.01 volts at the batteries they are probably good, at least without a load test, we'll assume the best for now. Sounds like at least until yesterday the starter was working but it has now gone dead. So it seems you either have a dead starter or ignition switch. Until yesterday you said it at least turned the engine, but it would try to start but not keep running. I think your problem at that point was lack of fuel. Possible causes are no fuel, (but you guarantee it has plenty), fuel pump inop, or a clogged in tank filter. Turn on ignition and see if you hear pump running (if your not sure put your hand on it, you'll feel it if its running) if its running take off the aircleaner and with a flashlight look down the throats, operate the throttle linkage and see if the accelerator pumps are squirting fuel, if not then no fuel is the problem. If pump runs and you have no fuel I'd bet the in tank filter is clogged. The tank will have to pumped out to remove and clean the filter. To solve for starter issue check for voltage at the large yellow wire at the solenoid when ignition is in the crank position, should be minimum of 12v. If 12v. is present at the solenoid then it most likely is a bad starter.

[PrairieDriver]

Thanks, Ed. You welcomed me to this forum when I posted about my metallic green '71 targa which is very similar to your own. I am fortunate to have you share your extensive expertise.

I will start working through your suggested sequence of steps. Hopefully I will be able to get into the garage before the weekend. I will report back.

[PrairieDriver]

Update: The fuel pump definitely works (and consistently, i.e., not intermittently). Next I took off the airbox to see if the accelerator pump is squirting fuel. This is where things got interesting (and startling!). I took video looking down a velocity stack to see if I could spot fuel moving through the carburetor. It took a few attempts to get a good view. On my last attempt I was startled to see a burst of fire (I am confident that the earlier attempts did not produce a flame).

I’ve attached a frame which shows the fire. I stopped after that!

I’m not sure how to interpret the fire. My conclusion: fuel is getting to the carburetor (!), although perhaps intermittently (if so, likely driven by a clogged fuel filter, as Ed surmises).

Should I move on to testing the starter (voltage check per Ed’s guidance)? That would require me to crank the engine again. I’d appreciate thoughts on the fire before going to that step.

Thanks for any thoughts.

[1QuickS]

Pretty cool-headed of you to film your carb fire...

Flooding Zeniths will pond fuel in the top of the top cover which is then very vulnerable to combustion. The top covers have external ribs which act like little fuel bowls to collect fuel that escapes the fuel chambers during flooding.

I think checking fuel levels in the float bowls would be good to perform but remove air cleaner housings and make sure you do not have fuel in the recesses of the top covers of the carbs. This requires an external fuel level vial to be performed accurately.

Zeniths do seem to have a problem with carb fires but more often during hot driving conditions when fuel percolation in the float bows will cause fuel to escape the float bowls.

Zenith floats are also a hard plastic that can absorb fuel and lose buoyancy which could be a source of flooding.

[edmayo]

So where are we now? The starter is cranking the engine, judging by the flames you have ignition, and there must be fuel. I hope you weren't pumping the throttle while cranking the engine? So once again, with the aircleaner off, and NOT cranking the engine, operate the throttle linkage and see if the accelerator pumps are squirting fuel. If you're seeing fuel squirt from the accel pumps then it should start. Start procedure is to pump throttle twice, but NOT while cranking over engine, then depress gas pedal about 2/3rds open, then crank engine! If it doesn't start STOP cranking, pump throttle several times again, then hold throttle down again and crank engine. You don't want to be pumping throttle while cranking over engine.

[PrairieDriver]

Thanks, Paul and Ed. I am very fortunate to have experts like you helping a newbie like me. I'm also fortunate to have not burned anything or anyone with yesterday's fire drama.

I will go through Ed's steps very carefully and with recognition that details and precision matter, even with seemingly basic matters such as how far to turn the key. I've gone back through my owner's manual to see exactly how Porsche describes the 0-1-2-3 key positions. Next up: make sure I know exactly where to look for fuel in the accelerator pump (so as to avoid needing too many attempts which seems to fill the float bowls).

Fingers crossed!